Support Neutron policy file in both .json and .yaml format

ansible/roles/neutron/tasks/config.yml

ansible/roles/neutron/templates/neutron-bgp-dragent.json.j2

ansible/roles/neutron/templates/neutron-dhcp-agent.json.j2

ansible/roles/neutron/templates/neutron-l3-agent.json.j2

...roles/neutron/templates/neutron-linuxbridge-agent.json.j2

...le/roles/neutron/templates/neutron-metadata-agent.json.j2

...le/roles/neutron/templates/neutron-metering-agent.json.j2

...eutron/templates/neutron-openvswitch-agent-xenapi.json.j2

...roles/neutron/templates/neutron-openvswitch-agent.json.j2

ansible/roles/neutron/templates/neutron-server.json.j2

ansible/roles/neutron/templates/neutron-sriov-agent.json.j2

ansible/roles/neutron/templates/neutron.conf.j2

...s/notes/neutron-support-policy-yaml-d573149c4efee7ad.yaml